Consider a cylindrical test specimen under a confining pressure of 20.69 MPa and an axial stress of 20.69 MPa with compression positive, so that in cylindrical coordinates
σzz = 20.69 σrr = 20.69 σθθ = 20.69
τrz = 0.0 τzθ = 0.0 τθr = 0.0
1 εrr , εzz , εθθ , γrz , γzθ , γθr ;
2 the axial stress σzz required to maintain a zero axial strain;
3 the strain energy and strain energy density, if the test specimen is an NX core with a height to diameter ratio of two. Note: E = 16.55 GPa, ν = 0.20, and the sample is isotropic.